My check engine light came on in early February. The code was p0420. The mechanic I talked to took a look at my Durango and told me it was the catalytic converter.

I had the converter replaced yesterday and had the check light turned off. I was driving last night and the check engine light came on again. Same code. What's next?

 

the most likely reason for that code is the post cat oxygen sensor, NOT the cat. the

 

+1 SS. That is the O2 sensor code. Replace them all at once. Use OEM dealer product only. Enjoy another 100k+ miles problem free in that area.

And BTW, find a new mechanic.

IndyDurango

 

+1 most mechanics are just lookin for money, which isn't right. Always do a little research on a check engine code first, I had the code, turns out it was because my vehicle requires 91 octane fuel, and the dealership put in 87. It threw a lot of codes at me, ran the tank almost empty filled it up with 91 and the code went away, but has came back a few times when I ran cheaper gas. I run Mobil gas in my R/T now and haven't had a light in 2 or months!

 

Replace the after cat O2 sensor with a NTK or Desno sensor, I would not use any other name brand.

 

Cool, thanks guys! The check light has gone off on its own for now. I will replace the o2 sensors if it comes on again.

But in the meantime, "The Rango" is getting better gas mileage with the new cat! :-)